Device for guiding a gas stream

ABSTRACT

A device for guiding a gas stream defines an inlet opening, an outlet opening and at least one angular offset which diverts the gas stream. The shell is assembled from a first shell part and a second shell part, wherein the first shell part defines the inlet opening and the outlet opening and has at least one connecting structure for the gas-tight connection of the device to a further gas-guiding component, and wherein the second shell part is configured to enclose the inlet opening and the outlet opening of the first shell part.

The present invention relates to an apparatus for conducting a gas flow, in particular an exhaust gas flow of an internal combustion engine, comprising a shell which defines an inlet opening, an outlet opening and at least one bend deflecting the gas flow.

It is frequently necessary in modern motor vehicles due to construction space restrictions to configure the exhaust train with an angle, for which purpose deflection shells of the above-named kind are used. Such deflection shells can in particular be used between two exhaust gas system elements, for example between a particulate filter and an exhaust pipe or between an exhaust pipe and a catalytic converter.

Gas conducting components of the category are typically welded to the upstream component and to the downstream component of the exhaust train. A flange connection can also be provided alternatively to a weld connection. In this case, the flanges belonging to the deflection apparatus are welded to the shell. However, an unwanted welding deformation can occur in this respect. In addition, due to the increased number of components and to the additional machining steps, the manufacturing costs for the exhaust gas system increase.

It is therefore an object of the invention to provide an apparatus for the angled conducting of a gas flow which can be manufactured easily and inexpensively as well as while avoiding welding deformation.

The object is satisfied by an apparatus having the features of claim 1.

In accordance with the invention, the shell is composed of a first shell part and of a second shell part, wherein the first shell part defines the inlet opening and the outlet opening and has at least one connection structure for the gas-tight connection of the apparatus to a further gas conducting component, and wherein the second shell part is configured for enclosing the inlet opening and the outlet opening of the first shell part.

The shell conducting the gas flow is therefore not configured in one part, but rather in at least two parts, for example in the form of two half-shells, wherein one shell part is configured for a gas-tight connection to the upstream gas conducting component and/or to the downstream gas conducting component and the second shell part so-to-say forms a cover. A particularly simple and compact construction thereby results. A respective connection structure is preferably provided both at the inlet opening and at the outlet opening. The first shell part can also be configured in two parts so that, for example, the inlet opening and the outlet opening are formed in different components. Since the connection structures, which can in particular be flanges, are already provided at the first shell part, a later welding of flanges can be dispensed with. This in particular has the advantage that no welding deformation occurs.

Further developments of the invention are set forth in the dependent claims, in the description and in the enclosed drawings.

The connection structure can in particular be configured in one piece with the first shell part, in particular molded thereto. The number of required components as well as the number of weld seams can thereby be reduced. A direct molding of a flange to a passage-like or tubular shell can be difficult. Due to the two-part design of the shell, the first shell part can, however, have a relatively flat design, whereby the molding on of the connection structure is facilitated.

The connection structure preferably comprises a flange, in particular a clamping flange. This allows a simple and, where required, releasable gas-tight connection to the further components of the exhaust gas system. The number of required weld seams can in particular be kept small by a flange connection.

The connection structure can comprise a pipe stub extending in parallel with the direction of flow of the gas flow. This facilitates the assembly of the deflection apparatus. For example, the pipe stub can be placed onto or plugged into a counter-pipe stub which is in turn provided at the upstream or downstream gas conducting component, that is e.g. projects from a catalytic converter or from a particulate filter.

In accordance with an embodiment of the invention, the pipe stub expands in a direction facing outwardly with respect to the shell. Such an expansion of the pipe stub forms per se a flange which can be adapted in a special manner to a counterpiece of a furthergoing exhaust gas system component.

In accordance with a further embodiment of the invention, the pipe stub is formed as a passage in a deep-drawing process and in particular has a flare at the end side as the expansion. The flare can advantageously form a flange for a V clip.

In accordance with a further embodiment of the invention, the first shell part is plate-shaped, whereas the second shell part is hood-shaped. This allows a particularly simple manufacture since the application of the openings as well as the provision of the connection structures can take place in a favorable manner at the plate-like unworked part.

In accordance with an embodiment of the invention, the shell defines two consecutive bends which preferably each deflect the gas flow by 90°. More pronounced deflections can thus also be effected by one and the same gas conducting apparatus.

The two bends preferably act in the same sense, i.e. the gas conducting apparatus forms a passage arrangement of C shape in longitudinal section. Such an embodiment is in particular advantageous when a particulate filter and an exhaust pipe to be connected to it are arranged directly next to one another. If the application requires, the two bends can also act as deflecting in opposite senses so that the gas conducting apparatus forms a passage arrangement of S shape in longitudinal section.

The invention also relates to an exhaust gas system, in particular for an internal combustion engine, which has an apparatus as described above.

The invention will be described in the following by way of example with reference to the drawings.

FIG. 1 is a perspective representation of a part of an exhaust gas train of a motor vehicle into which an apparatus in accordance with the invention for conducting a gas flow is integrated;

FIG. 2 is a lateral longitudinal sectional representation of the apparatus for conducting a gas flow shown in FIG. 1; and

FIG. 3 is a perspective representation of a first shell part of a shell of the apparatus for conducting a gas flow shown in FIG. 1.

In accordance with FIGS. 1 and 2, an exhaust gas system of an internal combustion engine comprises a diesel particulate filter 12 and an exhaust pipe 10 arranged downstream thereof through which a hot exhaust gas flow 13 flows during the operation of the exhaust gas system. The diesel particulate filter 12 and the exhaust pipe 10 are in this respect arranged next to one another such that their flow axes S1, S2 extend in parallel. To connect the diesel particulate filter 12 to the exhaust pipe 10, an apparatus for conducting the exhaust gas flow is provided in the form of a deflection shell 14 which defines a first bend 18 and a second bend 19. The two bends 18, 19 each effect a deflection of the exhaust gas flow 13 by 90° and act in the same sense. The deflection shell 14 thereby forms a passage arrangement of C shape in longitudinal section. An inlet opening 16 of the deflection shell 14 is in this respect adapted to an outlet opening 31 of the diesel particulate filter 12. An outlet opening 15 of the deflection shell 14 is equally adapted to an inlet opening 30 of the exhaust pipe 10. The inlet opening 16 and the outlet opening 15 of the deflection shell 14 are formed in circular shape in cross-section.

The deflection shell 14 is composed of a first shell part 35 and a second shell part 37, with the connection of the deflection shell 14 to the diesel particulate filter 12 as well as to the exhaust pipe 10 taking place exclusively via the first shell part 35. Specifically, the first shell part 35 in accordance with FIG. 2 has a plate-like base section 21 in which the inlet opening 16 and the outlet opening 15 are arranged next to one another. Starting from the margin of the inlet opening 16 and of the outlet opening 15, a respective connection structure 20 extends in the form of a passage 22 which extends in parallel with the direction of flow of the exhaust gas flow 13 and which has a flare 24 at its end side. As can be seen from FIGS. 1 and 2, the second shell part 37 is hood-shaped and encloses both the inlet opening 16 and the outlet opening 15. In other words, the hood-shaped second shell part 37 forms a cover of the deflection shell 14. It is understood that the two shell parts 35, 37 are connected to one another in a gas-tight manner.

The gas-tight connection of the deflection shell 14 to the diesel particulate filter 12 and to the exhaust pipe 10 takes place by means of two V clips 26, with the flares 24 of the passages 22 forming a flange for the V clips 26. Corresponding counter-flanges 25 are provided at the diesel particulate filter 12 and at the exhaust pipe 10.

As can be seen from FIG. 1, the exhaust gas flow 13 in the part of the exhaust train shown is respectively deflected by 180° by two further deflection shells 14 and is in so doing conducted from the exhaust pipe 10 to a catalytic converter 39 and further from the catalytic converter 39 to a further exhaust pipe not visible in FIG. 1.

Due to the two-part design of the deflection shell 14 and to the passages 22 integrated into the deflection shells 14, a particularly compact construction is possible, with only a few components being required overall for manufacturing the deflection shell 14. In addition, the number of weld seams which are required in the assembly of the exhaust train can be reduced. Since the connection structures 20 are molded directly to one of the shell parts—namely to the first shell part 35—no later welding on of flanges has to take place and problems due to welding deformation are avoided.

REFERENCE NUMERAL LIST

10 exhaust pipe

12 diesel particulate filter

13 exhaust gas flow

14 deflection shell

15 outlet opening of the deflection shell

16 inlet opening of the deflection shell

18 first bend

19 second bend

20 connection structure

21 plate-shaped base section

22 passage

24 flare

25 counter-flange

26 V clip

30 inlet opening of the exhaust pipe

31 outlet opening of the diesel particulate filter

35 first shell part

37 second shell part

39 catalytic converter

S1 flow axis of the exhaust pipe

S2 flow axis of the diesel particulate filter 

1-15. (canceled)
 16. An apparatus for conducting a gas flow, comprising a shell which defines an inlet opening, an outlet opening and at least one bend deflecting the gas flow, wherein the shell is composed of a first shell part and a second shell part, with the first shell part defining the inlet opening and the outlet opening and having at least one connection structure for the gas-tight connection of the apparatus to a further gas conducting component, and with the second shell part being configured for enclosing the inlet opening and the outlet opening of the first shell part.
 17. The apparatus in accordance with claim 16, wherein the apparatus is adapted to conduct an exhaust gas flow of an internal combustion engine.
 18. The apparatus in accordance with claim 16, wherein the connection structure is configured in one piece with the first shell part.
 19. The apparatus in accordance with claim 18, wherein the connection structure is molded to the first shell part.
 20. The apparatus in accordance with claim 16, wherein the connection structure comprises a flange.
 21. The apparatus in accordance with claim 16, wherein the connection structure comprises a clamping flange.
 22. The apparatus in accordance with claim 16, wherein the connection structure comprises a pipe stub extending in parallel with the flow direction of the gas flow.
 23. The apparatus in accordance with claim 22, wherein the pipe stub expands in a direction facing outwardly with respect to the shell.
 24. The apparatus in accordance with claim 22, wherein the pipe stub is formed as a passage in a deep-drawing process.
 25. The apparatus in accordance with claim 24, wherein the pipe stub has a bent portion at the end side as the expansion.
 26. The apparatus in accordance with claim 16, wherein the first shell part is plate-shaped and the second shell part is hood-shaped.
 27. The apparatus in accordance with claim 16, wherein the shell defines two consecutive bends which each preferably deflect the gas flow by 90°.
 28. The apparatus in accordance with claim 27, wherein the two bends act to deflect in the same sense.
 29. An exhaust gas system, comprising an apparatus having a shell which defines an inlet opening, an outlet opening and at least one bend deflecting the gas flow, wherein the shell is composed of a first shell part and a second shell part, with the first shell part defining the inlet opening and the outlet opening and having at least one connection structure for the gas-tight connection of the apparatus to a further gas conducting component, and with the second shell part being configured for enclosing the inlet opening and the outlet opening of the first shell part.
 30. The exhaust gas system in accordance with claim 29, wherein the exhaust gas system is adapted to conduct an exhaust gas flow of an internal combustion engine. 